CVE-2026-115602 in Gutenberg Blocks by Kadence Blocks Plugin
Summary
by MITRE • 10/26/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Liquid Web / StellarWP Gutenberg Blocks by Kadence Blocks kadence-blocks allows Stored XSS.This issue affects Gutenberg Blocks by Kadence Blocks: from n/a through 3.8.0.1.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/26/2026
The identified security flaw represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this vulnerability manifests as a Stored XSS within the Gutenberg Blocks by Kadence Blocks plugin for WordPress environments managed through Liquid Web and StellarWP infrastructure. The core technical deficiency lies in the application's failure to adequately sanitize user-supplied input before it is processed and subsequently rendered into HTML output stored on the server side. Unlike reflected XSS, where malicious scripts are executed immediately upon a victim visiting a crafted URL, this vulnerability allows an attacker to inject persistent malicious code that resides within the database or content storage of the target system. When other users or administrators access pages containing these compromised blocks, the browser interprets and executes the embedded script in the context of the vulnerable website's domain. This persistence mechanism significantly amplifies the risk profile because the payload does not require complex social engineering to trigger repeatedly; it remains active until manually removed from the content repository.
The operational impact of this vulnerability is severe due to its potential for widespread data theft and session hijacking. An attacker who successfully exploits this Stored XSS can execute arbitrary JavaScript code within the browser context of any user viewing the affected page. This capability enables the extraction of sensitive information such as authentication cookies, session tokens, and potentially personally identifiable information if displayed on the compromised pages. Furthermore, attackers may leverage this access to perform actions on behalf of authenticated users, including modifying site content, defacing webpages, or redirecting traffic to malicious sites designed for phishing attacks. In enterprise environments utilizing Liquid Web hosting, such a breach could compromise not only individual user accounts but also serve as an entry point for lateral movement within the broader network infrastructure if session tokens are reused across multiple services. The vulnerability affects versions of Kadence Blocks ranging from initial releases up through version 3.8.0.1, indicating that legacy installations and those未及时 updated to newer patches remain at significant risk.
From a classification perspective, this flaw aligns with CWE-79: Improper Neutralization of Input During Web Page Generation in the Common Weakness Enumeration standard. It also maps directly to MITRE ATT&CK technique T1059.007, which covers JavaScript execution under Command and Control or Execution tactics depending on the attacker's intent. The persistence nature of Stored XSS places it within the initial access and impact phases of an attack lifecycle, allowing adversaries to maintain a foothold without needing repeated exploitation attempts for each target user. Security teams must recognize that input validation alone is insufficient; output encoding specific to the HTML context where the data will be rendered is critical to preventing script injection.
Mitigation strategies should prioritize immediate remediation through software updates and rigorous input handling practices. The most effective defense is upgrading Kadence Blocks to a version later than 3.8.0.1, provided that the vendor has released patches addressing this specific sanitization failure. For organizations unable to upgrade immediately due to compatibility constraints with other plugins or themes, implementing Web Application Firewall rules can provide temporary protection by detecting and blocking requests containing known XSS payloads in post data or query parameters associated with block configurations. Additionally, developers should enforce strict output encoding using context-aware methods such as HTML entity encoding for all dynamic content rendered within Gutenberg blocks. Regular security audits focusing on how user inputs are processed through the WordPress REST API and frontend rendering engines will help identify similar latent vulnerabilities across other custom or third-party plugins integrated into the Liquid Web hosting environment.